Systems and methods for monitoring and controlling use of medical devices

ABSTRACT

A device carries a use monitoring element that possesses a state or condition that changes in response to use of the device and that is sensed when the device is presented for use. Reuse of the device is not permitted, if the use monitoring element indicates a prior use.

RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 11/638,958, filed 14 Dec. 2006, which is a divisional ofco-pending U.S. patent application Ser. No. 10/792,423, filed 3 Mar.2004, which is a divisional of U.S. patent application Ser. No.10/070,465, filed 14 Aug. 2002, now U.S. Pat. No. 6,733,495, whichclaims the benefit of provisional U.S. Patent Application Ser. No.60/152,749, filed 8 Sep. 1999, and entitled “Systems and Methods forMonitoring and Controlling Use of Medical Devices,” and which is also acontinuation-in-part of U.S. patent application Ser. No. 09/495,390,filed 31 Jan. 2000, and entitled “Systems and Methods for Monitoring andControlling Use of Medical Devices, now abandoned, and acontinuation-in-part of U.S. patent application Ser. No. 09/574,704,filed 18 May 2000, and entitled “Graphical User Interface for Monitoringand Controlling Use of Medical Devices, now U.S. Pat. No. 6,464,689,”and a continuation-in-part of U.S. patent application Ser. No.09/639,910 filed 16 Aug. 2000, and entitled “Unified Systems and Methodsfor Controlling Use and Operation of a Family of Different TreatmentDevices,” now abandoned.

FIELD OF THE INVENTION

The invention is directed to systems and methods for monitoring andcontrolling use of medical devices.

BACKGROUND OF THE INVENTION

Use of medical devices intended to treat or diagnose conditions of thebody can sometimes generate stress on the material or materials fromwhich the devices are made. The material stress can alter the physicalcharacteristics of the devices, making future performance of the devicesunpredictable.

In addition, exposure to blood and tissue during use can entrapbiological components on or within many medical devices. Despitecleaning and subsequent sterilization, the presence of entrappedbiological components can lead to unacceptable pyrogenic reactions.

The effects of material stress and damage caused during a single use ofa medical device, coupled with the possibility of pyrogen reactions evenafter resterilization, reasonably justify imposing a single userestriction upon many medical devices.

SUMMARY OF THE INVENTION

The invention provides systems and methods for monitoring andcontrolling use of a device for treating a tissue region. The systemsand methods provide the device and an element carried by the device forretaining use monitoring information. The systems and methods employ areader to download from the element the use monitoring information to acontroller for the device. The systems and methods cause the controllerto process the use monitoring information by pre-programmed rules toeither enable or disable operation of the device.

According to one aspect of the invention, the element retains usemonitoring information as an identification code unique to the device.The pre-programmed rules cause the controller to create a table byregistering unlike identification codes in memory as they are downloadedby the reader and to enable operation of the device when a newidentification code is registered in the table. The pre-programmed rulescause the controller to disable operation of the device when the givenidentification code matches an identification code in the table.

The element can express the identification code using, e.g., a magneticcore element, or a bar code strip, or a RFID tag, or by Hall effect, orby an array of fiber optics.

According to another aspect of the invention, the element retains usemonitoring information as a value reflecting time period of use of thedevice. The pre-programmed rules cause the controller to enableoperation of the device only when the value reflects a time period ofuse less than a prescribed maximum time period of use.

The element can express the value using, e.g., a magnetic core element,or a bar code strip, or a RFID tag, or a stepper motor.

According to another aspect of the invention, the element includes amagnetic core carried by the device having a logic state that changes inresponse to use of the device. In one embodiment, magnetic flux in onedirection about the core represents a logic one state and magnetic fluxin another direction about the core represents a logic zero state. Thecore, when initially installed in the device, possesses a logic onestate. Use of the device changes the logic state to a logic zero state.When the device is presented for use, the state of the core is sensed.If the core indicates a prior use (logic zero state), reuse of thedevice is not permitted.

According to another aspect of the invention, the element includes alatching relay carried by the device having a relay condition thatchanges in response to use of the device. In one embodiment, the relayis biased toward an electrically open condition. The relay can be movedand latched into an electrically closed condition. Prior to use, therelay is located in the electrically open condition. During use, therelay is moved and latched to the electrically closed condition. Whenthe device is presented for use, the position of the relay is sensed. Ifthe position indicates a prior use (latched closed condition), reuse ofthe device is not permitted.

According to another aspect of the invention, the element includes a useregister carried by the device that retains a digital value that changesin response to use of the device. In one embodiment, when the device ispresented for use, the value contained in the use register is sensed. Ifthe value indicates a prior use, reuse of the device is not permitted.

Features and advantages of the inventions are set forth in the followingDescription and Drawings, as well as in the appended Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a system for treating body sphinctersand adjoining tissue regions, which embodies features of the invention;

FIG. 2 is a perspective view, with portions broken away, of a deviceusable in association with the system shown in FIG. 1 having anoperative element for contacting tissue shown in a collapsed condition;

FIG. 3 is a perspective view, with portions broken away, of the deviceshown in FIG. 2, with the operative element shown in an expandedcondition;

FIG. 4 is a perspective view, with portions broken away, of the deviceshown in FIG. 2, with the operative element shown in an expandedcondition and the electrodes extended for use;

FIG. 5 is an enlarged view of the operative element shown in FIG. 4,with the electrodes extended for use;

FIG. 6 is a schematic view of a module that uses magnetic core memory tomonitor and control incidence of use of the device shown in FIG. 2;

FIG. 7 is a schematic view of a module that uses a latching relay tomonitor and control incidence of use of the device shown in FIG. 2;

FIG. 8 is a schematic view of a module that uses a micro-chip registerto monitor and control incidence of use of the device shown in FIG. 2;and

FIG. 9 is a schematic view of a module that uses an identification codeto monitor and control incidence of use of the device shown in FIG. 2.

The invention may be embodied in several forms without departing fromits spirit or essential characteristics. The scope of the invention isdefined in the appended claims, rather than in the specific descriptionpreceding them. All embodiments that fall within the meaning and rangeof equivalency of the claims are therefore intended to be embraced bythe claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows one embodiment of a system 10, which monitors and controlsthe use of an operative element 12. The system 10 is well adapted forassociation with single use, catheter-based devices. Therefore, in theillustrated embodiment, the operative element 12 is part of acatheter-based treatment device 26. It should be appreciated, however,that the system 10 is also adaptable for use with devices and methodsthat are not necessarily catheter-based.

A. The Treatment Device

In the illustrated embodiment, the device 26 includes a handle 28 made,e.g., from molded plastic. The handle 28 is sized to be convenientlyheld by a physician, to introduce the catheter tube 30 into the targetedtissue region.

The handle 28 carries a flexible catheter tube 30. The catheter tube 30can be constructed, for example, using standard flexible, medical gradeplastic materials. The catheter tube 30 has a distal end 34, whichcarries the operative element 12.

The operative element 12 can support, for example, a device for imagingbody tissue, such as an endoscope, or an ultrasound transducer. Theoperative element 12 can also support a device to deliver a drug ortherapeutic material to body tissue. The operative element 12 can alsosupport a device for sensing a physiological characteristic in tissue,such as electrical activity, or for transmitting energy to stimulate orform lesions in tissue.

In the illustrated embodiment, the device 26, in use, is intended totreat dysfunction of sphincters and adjoining tissue regions in theupper gastrointestinal tract, e.g., in the lower esophageal sphincterand adjacent cardia of the stomach, as well as in the lowergastrointestinal tract, e.g., in the intestines, rectum and anal canal.Still, it should be appreciated that the system 10 can be used inassociation with other devices and methods used to treat otherdysfunctions elsewhere in the body, which are not necessarilysphincter-related. For example, the various aspects of the inventionhave application in procedures requiring ablation of tissue throughoutthe body, or treatment of hemorrhoids, or restoring compliance to orotherwise tightening interior tissue or muscle regions.

In the illustrated embodiment, one function that the operative element12 is to perform is to apply energy in a selective fashion to a targetedbody region, which, for the purpose of illustration, can be the loweresophageal sphincter, or cardia, or both. The applied energy creates oneor more lesions, or a prescribed pattern of lesions, below the mucosalsurface of the esophagus or cardia. The subsurface lesions are formed ina manner that preserves and protects the mucosal surface against thermaldamage.

It has been discovered that natural healing of the subsurface lesionsleads to a physical tightening of the sphincter and/or adjoining cardia.The subsurface lesions can also result in the interruption of aberrantelectrical pathways that may cause spontaneous sphincter relaxation. Inany event, the treatment can restore normal closure function to thesphincter.

The structure of the operative element 12 to achieve this result canvary. A representative embodiment is shown in FIGS. 2 to 4, in which theoperative element 12 comprises a three-dimensional basket 56. The basket56 includes one or more spines 58, and typically includes from four toeight spines 58, which are assembled together by a distal hub 60 and aproximal base 62.

In the illustrated embodiment, an expandable structure 72 comprising aballoon is located within the basket 56. The balloon structure 72 can bemade, e.g., from a Polyethylene Terephthalate (PET) material, or apolyamide (non-compliant) material, or a radiation cross-linkedpolyethylene (semi-compliant) material, or a latex material, or asilicone material, or a C-Flex (highly compliant) material.

The balloon structure 72 presents a normally, generally collapsedcondition, as FIG. 2 shows. In this condition, the basket 56 is alsonormally collapsed about the balloon structure 72, presenting a lowprofile for deployment into the esophagus 10.

The catheter tube 30 includes an interior lumen, which communicates withthe interior of the balloon structure 72. A fitting 76 (e.g., asyringe-activated check valve) is carried by the handle 28. The fitting76 communicates with the lumen. The fitting 76 couples the lumen to asyringe 78 (see FIG. 3). The syringe 78 injects fluid under pressurethrough the lumen into the balloon structure 72, causing its expansion.

Expansion of the balloon structure 72 urges the basket 56 to open andexpand (see FIG. 3). The force exerted by the balloon structure 72, whenexpanded, is sufficient to exert an opening force upon the tissuesurrounding the basket 56.

Each spine 58 carries an electrode 66 (see FIG. 4). In the illustratedembodiment, each electrode 66 is carried within the tubular spine 58 forsliding movement. Each electrode 66 slides from a retracted position,withdrawn in the spine 58 (shown in FIG. 3) and an extended position,extending outward from the spine 58 (see FIG. 4) through a hole in thespine 58. A push-pull lever 68 on the handle 28 is coupled by one ormore interior wires to the sliding electrodes 66. The lever 68 controlsmovement electrodes between the retracted position (by pulling rearwardon the lever 68) and the extended position (by pushing forward on thelever 68). The electrodes 66 have sufficient distal sharpness andstrength, when extended, to penetrate a desired depth into tissue thesmooth muscle of the esophageal or cardia 20 wall. The desired depth canrange from about 4 mm to about 5 mm.

In this arrangement (see FIG. 1), the system 10 includes a generator 38to supply the treatment energy to the electrodes 66. In the illustratedembodiment, the generator 38 supplies radio frequency energy, e.g.,having a frequency in the range of about 400 kHz to about 10 mHz. Ofcourse, other forms of energy can be applied, e.g., coherent orincoherent light; heated or cooled fluid; resistive heating; microwave;ultrasound; a tissue ablation fluid; or cryogenic fluid.

A cable 40 extending from the proximal end of the handle 28 terminateswith an electrical connector 42. The cable 40 is electrically coupled tothe operative element 12, e.g., by wires that extend through theinterior of the handle 28 and catheter tube 30. The connector 42 plugsinto the generator 38, to convey the generated energy to the operativeelement 12.

The electrodes 66 are formed of material that conducts radio frequencyenergy, e.g., nickel titanium, stainless steel, e.g., 304 stainlesssteel, or a combination of nickel titanium and stainless steel.

In the illustrated embodiment (see FIG. 5), an electrical insulatingmaterial 70 is coated about the proximal end of each electrode 66. Whenthe distal end of the electrode 66 penetrating the smooth muscle of theesophageal sphincter 18 or cardia 20 transmits radio frequency energy,the material 70 insulates the mucosal surface of the esophagus 10 orcardia 20 from direct exposure to the radio frequency energy. Thermaldamage to the mucosal surface is thereby avoided. The mucosal surfacecan also be actively cooled during application of radio frequencyenergy, to further protect the mucosal surface from thermal damage.

In the illustrated embodiment (see FIG. 5), at least one temperaturesensor 80 is associated with each electrode. One temperature sensor 80senses temperature conditions near the exposed distal end of theelectrode 66, a second temperature sensor 80 is located on thecorresponding spine 58, which rests against the muscosal surface whenthe balloon structure 72 is inflated.

The system 10 (see FIG. 1) can also include certain auxiliary processingequipment, e.g., an external fluid delivery apparatus 44 for supplyingcooling liquid to the targeted tissue, e.g., through holes in thespines, and an external aspirating apparatus 46 for conveying liquidfrom the targeted tissue site, e.g., through other holes in the spine orelsewhere on the basket 56.

The system 10 also includes a controller 52. The controller 52, whichpreferably includes a central processing unit (CPU), is linked to thegenerator 38, the fluid delivery apparatus 44, and the aspiratingapparatus 46. Alternatively, the aspirating apparatus 46 can comprise aconventional vacuum source typically present in a physician's suite,which operates continuously, independent of the controller 52. Thecontroller 52 governs the delivery of processing fluid and, if desired,the removal of aspirated material.

The controller 52 also governs the power levels, cycles, and durationthat the radio frequency energy is distributed to the electrodes 66, toachieve and maintain power levels appropriate to achieve the desiredtreatment objectives. The controller 52 can condition the electrodes 66to operate in a monopolar mode. In this mode, each electrode 66 servesas a transmitter of energy, and an indifferent patch electrode (notshown) serves as a common return for all electrodes 66. Alternatively,the controller 52 can condition the electrodes 66 to operate in abipolar mode. In this mode, one of the electrodes comprises thetransmitter and another electrode comprises the return for thetransmitted energy. The bipolar electrode pairs can electrodes 66 onadjacent spines, or electrodes 66 spaced more widely apart on differentspines.

The controller 52 includes an input/output (I/O) device 54. The I/Odevice 54 allows the physician to input control and processingvariables, to enable the controller to generate appropriate commandsignals. The I/O device 54 also receives real time processing feedbackinformation from the temperature sensors 80, for processing by thecontroller 52, e.g., to govern the application of energy and thedelivery of processing fluid. The I/O device 54 also includes agraphical user interface (GUI), to graphically present processinginformation to the physician for viewing or analysis.

B. Monitoring and Control of Reuse

The handle 28 and the catheter tube 30 form an integrated constructionintended for a single use and subsequent disposal as a unit.Alternatively, the handle 28 can comprise a nondisposable componentintended for multiple uses. In this arrangement, the catheter tube 30,and components carried at the end of the catheter tube 30 comprise adisposable assembly, which the physician releasably connects to thehandle 28 at time of use and disconnects and discards after use. Thecatheter tube 30 can, for example, include a male plug connector thatcouples to a female plug receptacle on the handle 28.

To protect patients from the potential adverse consequences occasionedby multiple use, which include disease transmission, or material stressand instability, or decreased or unpredictable performance, thecontroller 54 includes a module 48 that monitors incidence of use of thedevice and prevents multiple use.

The module and its interaction with the device 26 can take variousforms.

1. Magnetic Core Memory

In one embodiment (see FIG. 6), the device 26 carries within its handle28 a magnetic core 82 comprising, e.g., a toroidal-shaped piece offerrite magnetic material. Magnetic flux in one direction about the core82 represents a logic one state and magnetic flux in another directionabout the core 82 represents a logic zero state. The core 82, wheninitially installed in the device 26, possesses a logic one state. Thelogic one state therefore indicates the absence of prior use of thedevice 26.

Whenever a device 26 is coupled to the generator 38, the controller 52operates the module 48 to sense the state of the core 82 prior toenabling the conveyance of radio frequency energy to the electrodes 66.In the illustrated embodiment, the module 48 includes a transformer 84comprising a primary winding 86, which passes through the core 82, and asecondary winding 88, which is located outside the core 82.

The transformer 84 is coupled to a current source 90. The module 48,when activated, passes current through the primary winding 86 in adirection that will set the core 82 to a logic zero state. If the core82 initially contained a logic one state, a pulse of voltage occurs atthe terminals of the secondary winding 88. The determination of whetherthe core 82 memory was set at a logic one state or logic zero stateprior to sampling by the module 48 is therefore indicated, respectively,by the presence or absence of a pulse in the secondary winding 88.

The controller 52 is coupled to the module 48. When a device 26 iscoupled to the generator 38, the controller 52 causes current to flowfrom the source through the primary winding 86 to set the core 82 tologic zero state. The controller 52 senses the presence or absence of avoltage pulse in the secondary winding 88. In the presence of a sensedvoltage pulse; the controller 52 enables the conveyance of radiofrequency energy to the device 26.

After a specified time period of use (e.g., at the end of a treatmentcycle or after a prescribed time out period), the controller 52 causescurrent to flow from the generator 38 through an amplifier 92 to thecore 82 in the direction that assures that the core 82 retains the logiczero state. The logic zero state of the core 82 therefore indicates thatthe device 26 has been used.

Should a device 26 having the core 82 set at the logic zero state beagain coupled to the generator 38, operation of module 48 to causecurrent to pass from the source 90 through the primary winding 86 willthis time result in the absence of a sensed pulse in the secondarywinding 88 (because the core 82 is already set at logic zero state).This condition identifies a device 26 that has been previously beenused.

In the absence of a sensed pulse, the controller 52 does not permitradio frequency energy to be conveyed to the device 26. The controller52 can also generate an output to the display device 54, that results ina visual or audible alarm, informing the operator that the device 26 hasbeen previously used and cannot be used again. The controller 52 alsocauses current to flow from the generator 38 through the amplifier tothe core 82 in the direction that assures that the core 82 of the device26 remains in a logic zero state.

2. Latching Relay

In another embodiment (see FIG. 7), the device 26 carries within itshandle 28 a latching relay 94. The latching relay 94 includes a switcharm 96 and a contact 98 coupled to ground. The switch arm 96 is biasedtoward an electrically open condition, away from the contact 98. Theswitch arm 96 can be moved into an electrically closed condition,against the contact 98.

In the illustrated embodiment, the latching relay 94 also includes acoil 100. When energized, the coil 100 moves the switch arm 96 to theelectrically closed condition. The latching relay 94 further includes apermanent magnet 102 that, once the switch arm 96 is moved into theelectrically closed condition, retains the switch arm 96 in theelectrically closed condition.

When initially installed in the device 26, the switch arm 96 is locatedin the electrically open condition. This is treated as a logic onestate. The logic one state indicates that the device 26 has not beenused.

Whenever a device 26 is coupled to the generator 38, the controller 52operates the module 48 to sense the position of the switch arm 96 priorto enabling the conveyance of radio frequency energy to the electrodes66.

In the illustrated embodiment, the module 48 includes a first circuit104 that applies current from a source 106 through a resistor 108 to theswitch arm 96. The presence or absence of current flow depends whetherthe switch arm 96 is in the electrically open condition (i.e., the logicone state) or in the electrically closed condition (which is treated asa logic zero state).

The module 48 also includes a second circuit 110 that applies currentfrom a source 112 the coil 100. The application of this current movesthe switch arm 96 to the electrically closed condition, which thepermanent magnet 102 maintains.

The controller 52 is coupled to the module 48. When a device 26 iscoupled to the generator 38, the controller 52 senses the presence ofcurrent flow through the first circuit 104. The absence current flow inthe first circuit 104 (i.e., the logic one state) indicates that theswitch arm 96 is in the electrically open condition. This conditionidentifies a device 26 that has not been previously used. The controller52 thereby enables the conveyance of radio frequency energy from thegenerator 38 to the device 26.

After a specified time period of use (e.g., at the end of a treatmentcycle or after a prescribed time out period), the controller 52 alsocauses current to flow in the second circuit 110. This current moves theswitch arm 96 to the electrically closed condition, which is the logiczero state, to indicate that the device 26 has been used.

In the illustrated embodiment, the controller 52 then resamples thecurrent flow through the first circuit 104, to confirm that the switcharm 96 has been successfully moved to the electrically closed condition.If, after current flow through the second circuit 110, no current flowis sensed in the first circuit 104 (indicating that the switch arm 96 isstill in the electrically open condition), the controller 52 generatesan error signal.

Should a device 26 having the switch arm 96 set at the logic zero statebe again coupled to the generator 38, the controller 52 will sense thepresence of current flow in the first circuit 104. This indicates prioruse of the device 26. In the presence of a current flow in the firstcircuit 104, the controller 52 does not permit radio frequency energy tobe conveyed to the device 26. The controller 52 can also generate anoutput to the display device 54 that results in a visual or audiblealarm, informing the operator that the device 26 has been previouslyused and cannot be used again.

3. Use Register

In another embodiment (see FIG. 8), the device 26 carries within itshandle 28 a use register 144. The use register 114 contains a digitalvalue that changes upon use of the device 26.

The use register 114 can comprise a solid state micro-chip, ROM, EEROM,EPROM, or non volatile RAM carried within the handle 28. The useregister 114 is initially programmed by the manufacturer of the device26, e.g., with a digital value of zero. The use register 114 includes anoutput 116 that generates this digital value upon prompting. The useregister 114 also includes an input 118 which increments the digitalvalue upon use of the device 26 to apply radio frequency energy.

Whenever a device 26 is coupled to the generator 38, prior to enablingthe conveyance of radio frequency energy to the electrodes 66, thecontroller 52 operates a module 48 to prompt the use register 114 tooutput the then resident digital value.

The controller 52 compares the digital value output to a set valueindicating no prior use, i.e., a zero value. A resident value of zeroidentifies a device 26 that has not be previously used. The controller52 thereby enables the conveyance of radio frequency energy from thegenerator 38 to the device 26.

After a specified time period of use (e.g., at the end of a treatmentcycle or after a prescribed time out period), the controller 52 alsogenerates an input to the use register 114, which increments theresident value to a value above zero, to indicate that the device 26 hasbeen used.

Should a device 26 with a use register 114 having a resident valuegreater than zero be again coupled to the generator 38, the controller52 will sense the incremented digital value. This indicates prior use ofthe device 26. In the presence of an incremented resident value greaterthan zero, the controller 52 does not permit radio frequency energy tobe conveyed to the device 26. The controller 52 can also generate anoutput to the display device 54 that results in a visual or audiblealarm, informing the operator that the device 26 has been previouslyused and cannot be used again.

The use register 114 can take other forms and retain a more detailedhistory of use. For example, the use register 114 can be configured toretain a value reflecting the actual period of time during which energyhas been applied to the device 26. For example, the use register 114 cancomprise an array of magnetic cores, which are embedded by thecontroller 54 with a pattern of magnetic states that, together, expressin binary terms the time-of-use. In this arrangement, the module 48includes sense amplifiers to determine the magnetic states of the arrayand, from that, derive the time-of-use history. Alternatively, the useregister 114 can comprise a material, e.g., relatively high coercivesquare loop material, which can be incrementally saturated by pulses ofmagnetism by the controller 54 over time, such that the magnitude of thecharge bears a linear relationship with time-of-use. In thisarrangement, the module 48 includes a sense amplifier to determine themagnitude of the charge and, from that, the time-of-use history.

As another example, the use register 114 can comprise a handle-residentmagnetic strip. One or more analog magnetic recording heads can be usedto record information on the strip during use. The module 48 cancomprise a bar-code reader, that reads the code in conventional fashion,e.g., as the user swipes the strip on the handle across the reader.Alternatively, the same heads in the handle can also be employed to readinformation from the strip for processing by the module 48.

As yet another example, the use register 114 can comprise a miniaturestepper or DC motor carried in the handle. The stepper motor operates asthe device 26 is used, e.g., to incrementally advance an arm insuccession across an array of electrical contacts. The stepper motoradvances the arm serially from one contact to another in proportion tothe length of time the device 26 is in use. The alignment between thearm and a particular electrical contact is electrically sensed by themodule 48, from which the time-of-use can be ascertained.

As yet another embodiment, the use register 114 can comprise aconventional RFID tag element carried within the handle. In thisarrangement, the module 48 includes an RFID transponder. The user scansthe tag element with the transponder before use, to ascertaintime-of-use information, and then scans the tag element with thetransponder after use to update the time-of-use information.

In these embodiments, the controller 54 can ascertain whether the timeperiod of previous use or uses retained by the use register 114 is lessthan a prescribed maximum time period, e.g., 45 minutes. If so, thecontroller 54 enables operation of the generator 38 in association withthe device 26, but only for the time period remaining. If the controller54 ascertains that the time period of previous use or uses equals orexceeds the prescribed maximum time period, the controller 54 does notenable use of the generator 38.

4. Device Identification Code

In another embodiment (see FIG. 9), the device 26 carries within itshandle 28 an element 200 that holds a value that constitutes a uniqueidentification code 214 capable of being read by the module 48 andregistered by the controller 54. The identification code 214 is createdto be unique to each device 26. That is, each device 26 contains its ownunique identification code 214. No two devices 26 share the sameidentification code 214. The unique identification code 214 cancomprise, e.g., a serial number uniquely assigned to the particulardevice 26, or any other unique code that is not repeated for any otherdevice 26. The code 214 itself can comprise letters, numbers, orcombinations thereof.

As FIG. 9 shows, when the device 26 is coupled to the controller 54, themodule 48 reads the identification code 214 for input to the controller54. This identification code will be called the “instant identificationcode.”

Following pre-programmed rules, the controller 54 constructs andmaintains in non-volatile memory a use table 216. The use table 216contains all prior identification codes that meet the criteria to beregistered by the controller 54. These identification codes will becalled the “registered identification codes.”

Following pre-programmed rules, the controller 54 compares the instantidentification code 214 to all registered identification codes containedin the table 216. In the absence of a match between the instantidentification code and any registered identification code, thecontroller 54 updates the table, i.e., the controller registers theinstant identification code by adding it to the table 216. Uponregistering the usage key card 202, the controller 54 also enables useof generator 38 in association with the device.

The presence of a match between the instant identification code and anyregistered identification code indicates a prior use of the device 26.In this circumstance, the controller 54 does not add the duplicativeidentification code to the table 216 and does not enable use of thegenerator 38 in association with any device 26. Preferably, thecontroller 54 outputs to the display device 54 a visual or audible alarmproviding notice of prior use.

The element 200 can take various forms. For example, the element 200 cancomprise an array of magnetic cores, which are embedded with a patternof magnetic states that, together, express a multiple bit binary valueexpressing the identification code. In this arrangement, the module 48includes sense amplifiers to determine the magnetic states of the arrayand, from that, derive the binary value.

As another example, the element 200 can comprise a strip containing amagnetic or optical bar code that expresses the identification code. Inthis arrangement, the module 48 comprises a bar-code reader, that readsthe code in conventional fashion, e.g., as the user swipes the strip onthe handle across the reader. Alternatively, the identification code canbe expressed by conventional RFID tag element carried within the handle.In this arrangement, the module 48 includes an RFID transponder, whichscans the tag element to read the code.

The binary bits of the identification code can also be expressed by Halleffect. In this arrangement, the module 48 can comprise either an arrayof Hall effect sensors, which read the multiple-bit identification codein parallel, or by a single, mechanically movable Hall effect sensor,which reads and processes the code bit-by-bit in a serial swipingmotion.

Alternatively, the element 200 can generate the identification code canbe expressed in a binary fashion using an array of fiber optics, eachfiber expressing a bit of the code. In this arrangement, the module 48can comprise an array of photo diodes, which read the multiple-bitoptical code in parallel, or by a single, mechanically movable photodiode, which reads and processes the optical code bit-by-bit in a serialswiping motion.

The controller 54 can also maintain for each registered identificationcode in the table 216 a time record 218. The time record 218 contains avalue reflecting the period of time during which energy was applied bythe generator 38 during the previous permitted use. In this embodiment,when a match occurs between the instant identification code and aregistered identification code, the controller 54 ascertains whether thetime period of previous use contained in the record 218 is less than aprescribed maximum time period, e.g., minutes. If so, the controller 54enables a subsequent operation of the generator 38 in association withthe device 26, but only for the time period remaining. The controller 54updates the time record 218 as further use occurs. The controller 54preferably outputs to the display device the time period of permitteduse remaining.

If the controller 54 ascertains that the time period of previous useequals or exceeds the prescribed maximum time period, the controller 54does not enable use of the generator 38. Preferably, the controller 54outputs to the display device notice of prior use.

Each embodiment of the module 48, as above described, assures that thedevice 26, once used, cannot be used a second time. The device 26, whensupplied to a customer, can also be accompanied by a floppy disk. Thedisk, when read by a disk drive associated with the controller 52,identifies the type of catheter in terms of its operationalcharacteristics, the inclusion of temperature sensing, and reusecriteria (e.g., no reuse after a single use, or multiple uses permittedup a prescribed maximum number of uses, or multiple uses permitted up toa maximum time period of use, or multiple uses permitted up to a maximumapplication of RF energy). The disk can also condition the graphicaluser interface to display the desired images and data formats, whichchange depending upon the treatment procedure using the device (e.g.,treatment of GERD, fecal incontinence, or urinary incontinence).

Various features of the invention are set forth in the following claims.

1. A system for treating a tissue region comprising a device including ausage regulating mechanism having a logic state being operable to be setto either a logic state of one or a logic state of zero, and a reader tosense the logic state and enabling operation of the device if the sensedlogic state is a pre-established one of the logic state of one and thelogic state of zero, the reader further operating, in response toenabling operation of the device, to change the sensed logic state tothe other one of the logic state of one and the logic state of zero toprevent subsequent operation of the device.
 2. A system as in claim 1wherein the usage regulating mechanism is a magnetic core.
 3. A systemas in claim 1 wherein the use regulating mechanism is a latching relay.4. A system as in claim 3 wherein the latching relay includes a switcharm operable to be set to a first position corresponding to a logicstate of one or a second position corresponding to a logic state ofzero.
 5. A system as in claim 1 wherein the device is adapted to applyradio frequency energy to the tissue region.
 6. A system for treating atissue region comprising a controller, and a device including a useregister that senses time-of-use of the device and inputs thetime-of-use to the controller, the controller including a processingfunction for processing the time-of-use to enable operation of thedevice if the time-of-use is less than a prescribed maximum time periodand to disable operation of the device if the time-of-use equals orexceeds the prescribed maximum time period.
 7. A system as in claim 6wherein the use register comprises an array of magnetic cores.
 8. Asystem as in claim 6 wherein the use register comprises a magneticstrip.
 9. A system as in claim 6 wherein the use register comprises astepper motor.
 10. A system as in claim 6 wherein the use registercomprises a RFID tag element.
 11. A system as in claim 6 wherein thedevice is adapted to apply radio frequency energy to the tissue region.